My name is John Zimmer. I'm the owner of Sound Representation, which specializes in the sale of high-end audio equipment. I really learned everything that I know about high-end audio from working at this store that we're sitting in right now, Stereo Exchange. I'm going to teach you what to look for when you want to shop for a stereo.
Evaluating speakers is a crucial part in putting together a great stereo system. The most important thing to do is to bring your own music to a speaker evaluation. It is imperative that you play something that you know intimately, otherwise you have no point of reference. It's important to have material with good dynamic range and varied instrumentation. If you are making an evaluation of mixed CD, try and use material that is sourced from a CD and not MP3s, as you will get a better idea of what the system can do. Conversely if all you listen to is MP3s, bring some of those too, so you can see how the system handles those too. Questions to ask yourself when listening speakers, how well do these speakers produce a stereo image? Do I need to be sitting right in between the 2 speakers in order to enjoy the music? Am I having an emotional response to the music? Am I hearing things that I have not heard before on music that I know very well?
The most important thing is to trust your ears. You are going to live with the speakers you buy, so buy the ones that sound best to you.